1873, "butter substitute made from beef fat," from French oléomargarine (1854), from oléine, a widely distributed natural fat (from Latin oleum "oil" + -ine, after glycerine), + margarine. It was regarded as a chemical compound of olein and margarine.
oleaginous
oleander
Oleg
oleo
oleo-
oleomargarine
olfaction
olfactory
Olga
oligarch
oligarchic